• Auto Scaling

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  1. Help Center
  2. Auto Scaling
  3. User Guide
  4. AS Management
  5. Scaling Actions
  6. Expanding Resources as Planned

Expanding Resources as Planned

A scaling action can be triggered periodically or based on certain rules to adjust resources. Take an online course selection web application as an example. This application is frequently used before a semester starts and seldom used during the semester. You can expand resources for this application based on predictable traffic.

To suit predictable traffic needs, you can configure a scheduled or periodic policy for expanding resources.

Procedure

  1. Log in to the management console.
  2. Click in the upper left corner and select the desired region and project.
  3. Under Computing, click Auto Scaling. In the navigation pane on the left, choose Instance Scaling.
  4. Locate the row containing the target AS group and click View AS Policy in the Operation column.
  5. Click Add on the displayed AS Policies page.
  6. Configure parameters. For details, see Table 1.
    Table 1 Parameters to be configured

    Parameter

    Description

    Example Value

    Policy Name

    Specifies the name of an AS policy.

    as-policy-p6g5

    Policy Type

    Select Scheduled or Periodic for expanding resources at a specified time.

    If you select Periodic, you are required to configure two more parameters:

    • Time Range

      Specifies a time range during which the AS policy can be triggered.

    • Interval
      • One day
      • One week
      • One month

    N/A

    Triggered At

    Specifies a time at which the AS policy is triggered.

    N/A

    Scaling Action

    Specifies an action and the number of instances.

    The following scaling action options are available:
    • Add

      Adds instances to an AS group when the scaling action is performed.

    • Reduce

      Removes instances from an AS group when the scaling action is performed.

    • Set to

      Sets the expected number of instances in an AS group to a specified value.

    • Add 1 instance
    • Add 10% instances

      The number of instances to be added is 10% of the current number of instances in the AS group. If the product of the current number of instances and the percentage is not an integer, AS automatically rounds the value up or down:

    • Rounds down the value that is greater than 1.
    • Rounds up the value that is greater than 0 and less than 1 to 1.

    Cooldown Period

    Specifies a period of time after each scaling action is complete. During the cooldown period, scaling actions triggered by alarms will be denied. Scheduled and periodic scaling actions are not restricted.

    NOTE:
    • If a scaling action is triggered by an AS policy, the cooldown period is that which is configured for that AS policy.
    • If a scaling action is triggered by manually changing the expected number of instances or by other actions, the cooldown period is that which is configured for the AS group.

    300s

  1. Click OK.

    The newly added AS policy is displayed on the AS Policy tab. In addition, the AS policy is in Enabled state by default.